A Caltech Library Service

Disk, Corona, Jet Connection in the Intermediate State of MAXI J1820+070 Revealed by NICER Spectral-timing Analysis

Wang, Jingyi and Mastroserio, Guglielmo and Kara, Erin and García, Javier A. and Ingram, Adam and Connors, Riley and van der Klis, Michiel and Dauser, Thomas and Steiner, James F. and Buisson, Douglas J. K. and Homan, Jeroen and Lucchini, Matteo and Fabian, Andrew C. and Bright, Joe and Fender, Rob and Cackett, Edward M. and Remillard, Ron A. (2021) Disk, Corona, Jet Connection in the Intermediate State of MAXI J1820+070 Revealed by NICER Spectral-timing Analysis. Astrophysical Journal Letters, 910 (1). Art. No. L3. ISSN 2041-8205. doi:10.3847/2041-8213/abec79.

[img] PDF - Published Version
See Usage Policy.

[img] PDF - Accepted Version
See Usage Policy.


Use this Persistent URL to link to this item:


We analyze five epochs of Neutron star Interior Composition Explorer (NICER) data of the black hole X-ray binary MAXI J1820+070 during the bright hard-to-soft state transition in its 2018 outburst with both reflection spectroscopy and Fourier-resolved timing analysis. We confirm the previous discovery of reverberation lags in the hard state, and find that the frequency range where the (soft) reverberation lag dominates decreases with the reverberation lag amplitude increasing during the transition, suggesting an increasing X-ray emitting region, possibly due to an expanding corona. By jointly fitting the lag-energy spectra in a number of broad frequency ranges with the reverberation model reltrans, we find the increase in reverberation lag is best described by an increase in the X-ray coronal height. This result, along with the finding that the corona contracts in the hard state, suggests a close relationship between spatial extent of the X-ray corona and the radio jet. We find the corona expansion (as probed by reverberation) precedes a radio flare by ~5 days, which may suggest that the hard-to-soft transition is marked by the corona expanding vertically and launching a jet knot that propagates along the jet stream at relativistic velocities.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Wang, Jingyi0000-0002-1742-2125
Mastroserio, Guglielmo0000-0003-4216-7936
Kara, Erin0000-0003-0172-0854
García, Javier A.0000-0003-3828-2448
Ingram, Adam0000-0002-5311-9078
Connors, Riley0000-0002-8908-759X
van der Klis, Michiel0000-0003-0070-9872
Dauser, Thomas0000-0003-4583-9048
Steiner, James F.0000-0002-5872-6061
Homan, Jeroen0000-0001-8371-2713
Lucchini, Matteo0000-0002-2235-3347
Fabian, Andrew C.0000-0002-9378-4072
Bright, Joe0000-0002-7735-5796
Fender, Rob0000-0002-5654-2744
Cackett, Edward M.0000-0002-8294-9281
Remillard, Ron A.0000-0003-4815-0481
Additional Information:© 2021. The American Astronomical Society. Received 2021 February 19; revised 2021 March 5; accepted 2021 March 7; published 2021 March 19. While this work was being finalized, we became aware of De Marco et al. (2021), showing the decrease in the observed soft lag frequency during the state transition, corroborating this aspect of our work. J.W., G.M., E.K., and J.A.G. acknowledge support from NASA grant 80NSSC17K0515, and thank the International Space Science Institute (ISSI) and participants of the ISSI Workshop "Sombreros and lampposts: The Geometry of Accretion onto Black Holes" for fruitful discussions. J.A.G. thanks the Alexander von Humboldt Foundation. A.I. and D.B. acknowledge support from the Royal Society.
Funding AgencyGrant Number
Alexander von Humboldt FoundationUNSPECIFIED
Subject Keywords:Low-mass x-ray binary stars; Stellar mass black holes; High energy astrophysics; Black hole physics; X-ray transient sources
Issue or Number:1
Classification Code:Unified Astronomy Thesaurus concepts: Low-mass x-ray binary stars (939); Stellar mass black holes (1611); High energy astrophysics (739); Black hole physics (159); X-ray transient sources (1852)
Record Number:CaltechAUTHORS:20210401-100722072
Persistent URL:
Official Citation:Jingyi Wang et al 2021 ApJL 910 L3
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:108605
Deposited By: Tony Diaz
Deposited On:01 Apr 2021 18:22
Last Modified:16 Nov 2021 19:12

Repository Staff Only: item control page